1995 jag xj6 cut off.

I have a 1995 Jag xJ6. 154k miles, engine rebuilt at 144k. I pulled into my garage, my car was idleing normal. 1 minute later it cut off. I tested the battery its good. The car is not getting any sound at all when the key is turned. The lights and radio all work, and the fan comes on when the the key is in the on position, but none of the dash instuments power up and my milage has all -------- (dashes) instead of numbers. The car will not even turn over nor am I getting the any sound out of the started or solenoid. Any Idea as to what has just transpired?